<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- This manual is for FFTW
(version 3.3.8, 24 May 2018).

Copyright (C) 2003 Matteo Frigo.

Copyright (C) 2003 Massachusetts Institute of Technology.

Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation
approved by the Free Software Foundation. -->
<!-- Created by GNU Texinfo 6.3, http://www.gnu.org/software/texinfo/ -->
<head>
<title>FFTW 3.3.8: Calling FFTW from Modern Fortran</title>

<meta name="description" content="FFTW 3.3.8: Calling FFTW from Modern Fortran">
<meta name="keywords" content="FFTW 3.3.8: Calling FFTW from Modern Fortran">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="index.html#Top" rel="up" title="Top">
<link href="Overview-of-Fortran-interface.html#Overview-of-Fortran-interface" rel="next" title="Overview of Fortran interface">
<link href="FFTW-MPI-Fortran-Interface.html#FFTW-MPI-Fortran-Interface" rel="prev" title="FFTW MPI Fortran Interface">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en">
<a name="Calling-FFTW-from-Modern-Fortran"></a>
<div class="header">
<p>
Next: <a href="Calling-FFTW-from-Legacy-Fortran.html#Calling-FFTW-from-Legacy-Fortran" accesskey="n" rel="next">Calling FFTW from Legacy Fortran</a>, Previous: <a href="Distributed_002dmemory-FFTW-with-MPI.html#Distributed_002dmemory-FFTW-with-MPI" accesskey="p" rel="prev">Distributed-memory FFTW with MPI</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Calling-FFTW-from-Modern-Fortran-1"></a>
<h2 class="chapter">7 Calling FFTW from Modern Fortran</h2>
<a name="index-Fortran-interface-2"></a>

<p>Fortran 2003 standardized ways for Fortran code to call C libraries,
and this allows us to support a direct translation of the FFTW C API
into Fortran.  Compared to the legacy Fortran 77 interface
(see <a href="Calling-FFTW-from-Legacy-Fortran.html#Calling-FFTW-from-Legacy-Fortran">Calling FFTW from Legacy Fortran</a>), this direct interface
offers many advantages, especially compile-time type-checking and
aligned memory allocation.  As of this writing, support for these C
interoperability features seems widespread, having been implemented in
nearly all major Fortran compilers (e.g. GNU, Intel, IBM,
Oracle/Solaris, Portland Group, NAG).
<a name="index-portability-4"></a>
</p>
<p>This chapter documents that interface.  For the most part, since this
interface allows Fortran to call the C interface directly, the usage
is identical to C translated to Fortran syntax.  However, there are a
few subtle points such as memory allocation, wisdom, and data types
that deserve closer attention.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top">&bull; <a href="Overview-of-Fortran-interface.html#Overview-of-Fortran-interface" accesskey="1">Overview of Fortran interface</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Reversing-array-dimensions.html#Reversing-array-dimensions" accesskey="2">Reversing array dimensions</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="FFTW-Fortran-type-reference.html#FFTW-Fortran-type-reference" accesskey="3">FFTW Fortran type reference</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Plan-execution-in-Fortran.html#Plan-execution-in-Fortran" accesskey="4">Plan execution in Fortran</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Allocating-aligned-memory-in-Fortran.html#Allocating-aligned-memory-in-Fortran" accesskey="5">Allocating aligned memory in Fortran</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Accessing-the-wisdom-API-from-Fortran.html#Accessing-the-wisdom-API-from-Fortran" accesskey="6">Accessing the wisdom API from Fortran</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top">&bull; <a href="Defining-an-FFTW-module.html#Defining-an-FFTW-module" accesskey="7">Defining an FFTW module</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">
</td></tr>
</table>




</body>
</html>
